Automotive applications are requiring increased use of RF/microwave frequency bands, from low RF signals through millimeter-wave frequencies at 77 GigaHertz (GHz). As these high-frequency signals become more integral parts of the worldwide driving experience, effective test solutions become more critical for designers developing new automotive RF/microwave circuits, as well as production facilities seeking efficient methods for verifying the performance of these added circuits. While lower-frequency testers are in abundance, and automotive applications employ a wide range of wireless frequencies—including remote keyless entry (RKE) systems at 433 and 868 MHz—a growing concern in automotive markets is for the accurate and cost-effective testing of 77 GHz automotive radar systems. This interest stems from the fact that historically, measurement equipment at such high frequencies has neither been commonplace nor cost-effective.
A number of different automotive radar-based safety applications make use of frequencies from 76 to 77 GHz, for adaptive cruise control (ACC), blind-spot detection (BSD), emergency braking, forward collision warning (FCW), cross-traffic alert (CTA), lane change assist (LCA), and rear collision protection (RCP). For example, in a collision warning system, an automotive radar sensor can detect and track objects within the range of the transmitted and returned radar signals, automatically adjusting a vehicle's speed and distance in accordance with the detected targets. Different systems can provide a warning of a potential collision ahead and also initiate procedures leading to emergency braking as required.